(1) Field of the Invention
This invention relates in general to a level, and more particularly to a level comprising a base having a top reference edge and a recession adjacent to the top recession edge; and a slidable member that fits within the recession of the base wherein the member is slidable to extend the top reference edge of the base for multiple lengths.
(2) Background Art
The present invention relates to a level used in carpentry or construction, and more particularly, to an extendible level.
A level is an instrument or indicating tool used to ascertain true vertical, horizontal or 45 degrees with regard to a given surface. Typically such levels consist of a linear framework with liquid filled tubes placed strategically within the framework. Each liquid filled tube contains an air bubble which indicates by its position in the tube whether a surface is horizontally or vertically level. Such instruments may also be used to indicate whether the surface is a true 45 degrees. When the instrument is set on a true even plane the air bubble in the tube centers itself exactly in an indication window. Conversely, the air bubble that is not centered may indicate to what degree the surface is not horizontal or vertical. Such tubes may be filled with alcohol or ether. These well known tubes may be commonly referred to as level bubbles or spirit bubbles.
Levels are used in all areas of construction and are particularly necessary with regard to installing walls, doors, panels, frames, etc. Levels used in building construction or carpentry are available in all shapes and sizes. However, if a level is not long enough for a surface and has to be moved to different places on a surface, the accuracy of the resultant indications of the level is reduced. A level becomes more susceptible to error when it moves between points on a surface. The most accurate results are for a level that can cover the exact length of the surface to be leveled. However, such levels would be too big and cumbersome at certain lengths.
Prior art levels that are extendible to different lengths are available in the industry. Such extendible levels, however, do not allow for a continuous edge or top line of the level for scribing a level line. Furthermore, such available extendible levels are complicated and not easy to use during the process of leveling. The extendible parts of the prior art levels must be put into place before placing on a surface or leveling a surface. Moreover, they do not provide for a continuous reference level line.
Furthermore, prior art extendible levels do not have a system or a method to level right angles or in a protractor type arrangement. Such arrangements would be desirable to accurately level the more intrinsic designs in the field of construction and carpentry.
Thus, there is a need to provide an extendible level that allows for a continuity of measurement of a surface. There is a further need to provide a level that extends a top reference line for accurately leveling different lengths of a surface. Such an extendible level needs to be easily and smoothly extendible so that during the process of leveling it may be extended to different lengths. Such levels need to be easy to use, accurate and uncomplicated to manufacture.